public static ADCS GetADCS(SearchResultEntry csEntry)
{
logger.Debug("Collecting ADCS");
string enrollServers = null;
List <string> certTemplates = new List <string>();
List <X509Certificate2> caCertificates = new List <X509Certificate2>();
DACL acl;
string caHostname = csEntry.Attributes["dnshostname"][0].ToString();
string caName = csEntry.Attributes["name"][0].ToString();
string whenCreated = Helper.ConvertWhenCreated(csEntry.Attributes["whencreated"][0].ToString()).ToString();
var enrollmentEndpoints = AsyncCollection.TestEnrollmentEndpointsAsync(caName, caHostname).Result;
PkiCertificateAuthorityFlags flags = (PkiCertificateAuthorityFlags)Enum.Parse(typeof(PkiCertificateAuthorityFlags), csEntry.Attributes["flags"][0].ToString());
//The target attribute may not exist
foreach (string attribute in csEntry.Attributes.AttributeNames)
{
if (attribute == "certificatetemplates")
{
foreach (var certTemp in csEntry.Attributes[attribute])
{
certTemplates.Add(Encoding.UTF8.GetString((byte[])certTemp));
}
}
if (attribute == "mspki-enrollment-servers")
{
enrollServers = csEntry.Attributes[attribute][0].ToString().Replace("\n", ",");
}
if (attribute == "cacertificate")
{
caCertificates = GetCaCertificate(csEntry.Attributes[attribute]);
}
}
bool allowSuppliedSAN = false;
bool usingLDAP;
var remoteReg = Helper.ReadRemoteReg(caHostname,
RegistryHive.LocalMachine,
$"SYSTEM\\CurrentControlSet\\Services\\CertSvc\\Configuration\\{caName}\\PolicyModules\\CertificateAuthority_MicrosoftDefault.Policy");
//If the remote registry cannot be accessed, using LDAP to retrieve security descriptor instead
usingLDAP = remoteReg == null ? true : false;
if (usingLDAP)
{
acl = DACL.GetACLOnObject(csEntry.DistinguishedName);
}
else
{
int editFlags = (remoteReg == null) ? 0 : (int)(remoteReg).GetValue("EditFlags");
allowSuppliedSAN = ((editFlags & 0x00040000) == 0x00040000);
//Reading DACL from the remote registry, nTSecurityDescriptor from LDAP does not have the necessary information
var regSec = (byte[])(Helper.ReadRemoteReg(caHostname,
RegistryHive.LocalMachine,
$"SYSTEM\\CurrentControlSet\\Services\\CertSvc\\Configuration\\{caName}")).GetValue("Security");
var regSecDescriptor = new ActiveDirectorySecurity();
regSecDescriptor.SetSecurityDescriptorBinaryForm(regSec, AccessControlSections.All);
acl = DACL.GetCSACL($"{caHostname}:{RegistryHive.LocalMachine}:SYSTEM\\CurrentControlSet\\Services\\CertSvc\\Configuration\\{caName}", regSecDescriptor, out _, false);
}
return(new ADCS()
{
flags = flags,
caCertificates = caCertificates,
allowUserSuppliedSAN = allowSuppliedSAN,
CAName = caName,
whenCreated = whenCreated,
dnsHostName = caHostname,
enrollServers = enrollServers,
DACL = acl,
certTemplates = certTemplates,
enrollmentEndpoints = enrollmentEndpoints
});
}
public static CertificateTemplate GetInterestingCertTemplates(SearchResultEntry certTemplateResultEntry)
{
bool isPublished = false;
string publishedBy = null;
ActiveDirectorySecurity adRights = new ActiveDirectorySecurity();
byte[] ldapSecBytes = (byte[])certTemplateResultEntry.Attributes["ntsecuritydescriptor"][0];
adRights.SetSecurityDescriptorBinaryForm(ldapSecBytes, AccessControlSections.All);
var acl = DACL.GetCSACL(certTemplateResultEntry.DistinguishedName,
adRights,
out bool hasControlRights, true);
var enrollFlag = (msPKIEnrollmentFlag)Enum.Parse(typeof(msPKIEnrollmentFlag), certTemplateResultEntry.Attributes["mspki-enrollment-flag"][0].ToString());
var raSig = int.Parse(certTemplateResultEntry.Attributes["mspki-ra-signature"][0].ToString());
var certNameFlag = (msPKICertificateNameFlag)Enum.Parse(typeof(msPKICertificateNameFlag), (unchecked ((uint)(Convert.ToInt32(certTemplateResultEntry.Attributes["mspki-certificate-name-flag"][0].ToString())))).ToString());
List <string> ekus = new List <string>();
List <string> ekuNames = new List <string>();
if (certTemplateResultEntry.Attributes.Contains("pkiextendedkeyusage"))
{
foreach (byte[] eku in certTemplateResultEntry.Attributes["pkiextendedkeyusage"])
{
string ekuStr = Encoding.UTF8.GetString(eku);
ekus.Add(ekuStr);
ekuNames.Add(new Oid(ekuStr).FriendlyName);
}
}
//If a low priv user has control rights over the templates
if (hasControlRights)
{
foreach (var ca in ADCS.CertificateServices)
{
var certInCa = ca.certTemplates.FirstOrDefault(caCerts => caCerts.Contains(certTemplateResultEntry.Attributes["name"][0].ToString()));
if (certInCa != null)
{
isPublished = true;
publishedBy = ca.CAName;
}
}
return(new CertificateTemplate
{
IsPublished = isPublished,
PublishedBy = publishedBy,
CertNameFlag = certNameFlag,
RaSigature = raSig,
EnrollFlag = enrollFlag,
TemplateCN = certTemplateResultEntry.Attributes["cn"][0].ToString(),
TemplateDisplayName = certTemplateResultEntry.Attributes["displayName"][0].ToString(),
ExtendedKeyUsage = ekuNames,
DACL = DACL.GetACLOnObject(certTemplateResultEntry.DistinguishedName)//retrieve the complete DACL instead of interesting ACEs
});
}
//If a low priv user can enroll
else if (acl != null)
{
logger.Debug("Checking manager approval...");
//Check if manager approval is enabled
if (!enrollFlag.HasFlag(msPKIEnrollmentFlag.PEND_ALL_REQUESTS))
{
logger.Debug(certTemplateResultEntry.DistinguishedName);
logger.Debug("Checking authorized signatures...");
//Check if authorized signatures are required
if (raSig <= 0)
{
logger.Debug(certTemplateResultEntry.DistinguishedName);
logger.Debug("Checking EKUs & ENROLLEE_SUPPLIES_SUBJECT ...");
//Check if ENROLLEE_SUPPLIES_SUBJECT is enabled and a low priv user can request a cert for authentication
//Check if the template has dangerous EKUs
logger.Debug(certTemplateResultEntry.DistinguishedName);
if ((certNameFlag.HasFlag(msPKICertificateNameFlag.ENROLLEE_SUPPLIES_SUBJECT) && HasAuthenticationEKU(ekus)) || HasDanagerousEKU(ekus))
{
logger.Debug(certTemplateResultEntry.DistinguishedName);
foreach (var ca in ADCS.CertificateServices)
{
var certInCa = ca.certTemplates.FirstOrDefault(caCerts => caCerts.Contains(certTemplateResultEntry.Attributes["name"][0].ToString()));
if (certInCa != null)
{
isPublished = true;
publishedBy = ca.CAName;
}
}
if (acl.ACEs.Count != 0)
{
return(new CertificateTemplate
{
IsPublished = isPublished,
PublishedBy = publishedBy,
CertNameFlag = certNameFlag,
RaSigature = raSig,
EnrollFlag = enrollFlag,
TemplateCN = certTemplateResultEntry.Attributes["cn"][0].ToString(),
TemplateDisplayName = certTemplateResultEntry.Attributes["displayName"][0].ToString(),
ExtendedKeyUsage = ekuNames,
DACL = DACL.GetACLOnObject(certTemplateResultEntry.DistinguishedName)//retrieve the complete DACL instead of interesting ACEs
});
}
}
}
}
}
return(null);
}